路基拓宽工程设计方法研究

针对路基拓宽工程的实际问题,基于大量实体工程调研和理论分析,从损坏类型和损坏机理出发,揭示了路基拓宽工程中的4种损坏模式,包括路基结合部剪切开裂、新老路面结合部弯拉开裂、老路基层顶面开裂和新路基层底面开裂,建立了以变坡率为设计指标的路基拓宽设计方法;并遵循变形协调与控制的基本思想,着重提出了路基拓宽工程处治措施的选择流程,继而采用有限元计算和室内模拟试验的方法,对新老路基结合面处治、拓宽路基填料及压实度控制、路基加筋、支档结构等多种处治措施的处治机理、效果和设计施工要点进行了总结。各项研究成果对路基拓宽工程中处治措施的选择、设计和施工具有重要的借鉴和指导意义。

Design Philosophy of Subgrade Widening Engineering

On the basis of the in-situ investigation and analysis of the distresses caused by subgrade widening,the four failure modes in subgrade widening engineering are summarized,i.e.shear cracking in subgrade combination,tensile cracking in pavement interface,bottom-up tensile cracking in widening pavement and top-down tensile cracking in existing one,and then the correspond design philosophy,design criteria and the method of treatments selection are proposed according to the principle of differential deformation control.At last,through finite element analysis and laboratory simulation tests,the method and effect of different kinds of treatments are analyzed particularly,including control of filling and compaction,reinforcement,retaining structure,ect.The conclusion may be useful to the selection,design and construction of treatments in widening subgrade engineering.